1. Field of the invention
This invention relates generally to signal recording apparatuses and, more particularly, to a signal recording apparatus which is driven, for example, by a battery and applied for a recording medium, such as an MD, MO, DVD, CD-R, CD-RW or IC card, in which one or more of data and data management information are recorded.
2. DESCRIPTION OF THE RELATED ART
There is one example of a conventional signal recording apparatus of this kind as disclosed in a publication of Japanese Patent Laid-open No. H5-54517 [G11B 19/00, G11B 20/10, G11B 27/10] laid open on Mar. 5, 1993. In this prior art, if a battery voltage goes below a predetermined threshold during recording digital data onto an magnet-optical disk, TOC (Table Of Contents) information is recorded to the magnet-optical disk, thus finishing the operation. In this manner, effective reproducing of record data is possible by recording TOC information in advance of running down of a battery.
However, if a voltage greater than an actual voltage is detected due to low accuracy, recording of digital data would continue even after the actual voltage becomes lower than the threshold. This however results in a problem that the operation is finished without recording TOC information. On the other hand, if the threshold is given higher in order to avoid such a problem, another problem occurs that the operation comes to an end before fully using the battery thus reducing recording time.
Therefore, it is a primary object of the present invention to provide a signal recording apparatus which is capable of recording a desired signal completely.
A signal recording apparatus according to the present invention is a signal recording apparatus to be driven by a battery and record one or more of data and management information for managing the data to a recording medium, comprising: a detecting means for detecting a voltage value of the battery; a first comparing means for comparing detection result of the detecting means with a first threshold at which recording is possible to start; a second comparing means for comparing a detection result of the detecting means with a second threshold at which recording is possible to continue; a record starting means for starting to record the data depending upon a comparison result of the first comparing means; and a record continuing means for continuing to record the data depending upon a comparison result of the second comparing means.
The signal recording apparatus is driven by a battery and records one or more of data and data management information to a recording medium. The detecting means detects a voltage value of the battery. The first comparing means compares a detected voltage value with a first threshold that recording is possible to start. Also, the second comparing means compared the detected voltage value with a second threshold that record is possible to continue. The record start means starts to record a signal to the recording medium depending on a comparison result of the first comparing means. During recording of data, the record continuing means continues the recording depending on a comparison result of the second comparing means. In this manner, it is possible to start and continue data recording depending on a battery voltage value.
According to the invention, when a voltage value is in that recording is possible to start, recording of data is started thus preventing the recording from finishing in the course thereof. It is therefore possible to completely record a desired signal.
For this reason, the first threshold is set at a value that makes it possible to complete recording to the recording medium. In this case, the second management information recording means, when data recording is completed, records management information about all the data having been recorded before the completion of recording. Due to this, it is possible to positively reproduce all the recorded data.
In one aspect of the invention, a signal recording apparatus further comprises a caution means. When the detection result is lower than the first threshold, the caution means gives a caution of remaining capacity insufficiency of the battery. Accordingly, the user can charge or exchange the battery according to the caution.
In one embodiment of the invention, a signal recording apparatus further comprises a interruption means. When the voltage value is lower than the second threshold, the interruption means interrupts recording of data. Where data recording is interrupted in this manner, the first management information recording means records management information about all the data having been recorded before the interruption. Accordingly, even where the battery encounters insufficiency during recording data and finishes the recording in the course thereof, it is possible to reproduce the data having been so far recorded.
In this embodiment, the second threshold is set at a value that can record, after data record interruption, management information about all the data having been recorded before the interruption. Accordingly, even where there is necessity of suspending data recording, management information can be positively recorded. Therefore, the data recorded before interruption is possible to reproduce.
In another embodiment of the invention, a signal recording apparatus further comprises a determining means. The determining means, when recording of data is started in the signal recording apparatus, determines whether in waiting for data write or in writing data. Also, the second threshold includes a third threshold for a case of in waiting for writing data and a fourth threshold for a case of in writing data. Consequently, the interruption means finishes recording of the data when the voltage value during waiting for data writing is lower than the third threshold. Also, if the voltage value during data writing is lower than the fourth threshold, data recording is interrupted. In this manner, determination whether or not recording is possible to continue is made based on a different threshold depending on during data writing or in waiting for data writing. This makes determination higher in accuracy. It is therefore possible to effectively use the battery.
The above described objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.